In the depths of the ocean lives an extraordinary fish with a transparent head called the Barreleye Fish. It is one of the strangest-looking fish in the deep sea.
The dark dots above its mouth are not its eyes. The actual eyes are located in the transparent part of the head. The eyes are mostly directed upwards, but they can also look forward. This allows the fish while resting and “going with the flow,” to spot potential prey. The Barreleye Fish have large eyes that allow more light to enter, and they appear green due to a pigment that helps them absorb the wavelengths of light at the depths where they live.
Scientists believe that the fish steals food from siphonophores, and the transparent head helps protect its eyes from the powerful stings of siphonophores. These fish live between the mesopelagic and bathypelagic zones (400 – 2500m). They are pelagic spawners, which means they release a massive amount of eggs into the water to be fertilized by the males.